1. Field of the Invention
The present invention relates to a voltage providing circuit and a related method, and particularly relates to a voltage providing circuit for an LCD driving circuit and related method.
2. Description of the Prior Art
In an LCD driving circuit, a charge pump is always used for providing different desired voltages. For example, a source in a LCD matrix needs a voltage of 0˜6 V to provide different color depths, but a gate needs a voltage of 6˜12V. Furthermore, different states of LCDs need different amounts of current. For example, a larger current is needed when an image is transformed from black to white, but other states of the LCD require smaller currents. A redundant current, however, will not flow back to the charge pump after the charge pump voltage is increased, thus the redundant current is consumed and the power consumption increases. The more frequently the charge pump increases the voltage, the larger the power consumption.
Therefore, in order to decrease power consumption, a high frequency clock signal should not be provided to the charge pump unless necessary.